Can anyone answer this writing question?

Test Preparation SAT Preparation
1

<p>(A)(That) the country is now politically stable and economically robust (B)(and will) almost certainly continue (C)(to do so) (D)(is) no longer seriously doubted. (E)(No error)</p>

<p>The correct answer is C, and I chose E. I knew this question seemed awkward, but I don't know why C is correct.</p>

<p>Does anyone know?</p>

2

<p>The sentence is saying that the country “is” something, which is a form of “to be” so it should be “continue to be so”.</p>

3

<p>thank you!</p>