I want some help regarding the number of subjects I should have in my A levels. I already have three subjects in my A levels: physics, chemistry, and math. People usually tend to have 4-5 subjects, so my number of subjects just fulfill the minimum requirement and are hence on the lower side. I’ve heard that competitive colleges such as Cornell and Columbia really value the number of subjects in A-levels. I myself wanted to take 5 subjects but my parents did not allow me as they wanted me to focus on my three core subjects. However, now aware of the competition for colleges such as Columbia, my parents have now allowed me to take 5 subjects in my second year. I want to take environmental management and sociology but I beleive colleges would find that I have taken the two extra subjects in my second year to increase my chances of admission which would go against me. It is to be noted that even if I take these two subjects, they would not appear on my A1 transcript. Also how much of a drawback would be 3 subjects in my A levels. I need to take a call quickly and therefore I need your help.
Heyyy
Before you read further, just keep in mind that this is just my opinion, you can accept or reject it. But when you make a choice, listen to what you want the most, and just go with it.
So the thing is that taking 5 subjects will not guarantee you admission at Columbia. A lot of other factors will come into account: test scores, essays, extracurriculars, recommendations, etc.
As far as you taking 5 subjects in A2 is a concerned, don’t think that colleges will assume you did it just to increase your chances of admission for two reasons: 1. Don’t ever assume anything about colleges, and 2. If it shows something it is that you are willing to constantly challenge yourself by taking rigorous coursework.
I’m not sure about Environmental Management, but Sociology can be both easy and difficult to handle. Easy because if you find it interesting you will love it, and you’ll remember most of the information - something people might struggle with. Difficult in the sense that it would be challenging to get all the work done within a year, alongside you college apps, standardized tests (if you haven’t already done that), and the rest of your subjects.
BUT if you have the will there is no problem at all. I have seen people take up subjects like further math in A2, and get all A*s.
There are also numerous examples of people from Pakistan, getting into places like UPenn, Dartmouth, Cornell, Williams etc with 4 subjects. If you really want to take up more subjects, just take 4. And work on making the rest of your application great.
Hope that helped. GOOD LUCK WITH COLLEGE! 
I think you should take one more, perhaps sociology to show intellectual versatility. Would you take the exam? If so, you’d list all 4 on Common app, without distinguishing between those you started this year and the one you started before.