<p>The reason first novels are so often their writers' best work (is that it draws upon) all the experiences of childhood.</p>
<p>a- is that it draws upon
b- is that these first efforts draw upon
c- is because of these first efforts drawing from
d- is because of them drawing upon
e- is their drawing from</p>
<p>i foolish chose e. can someone explain why b is correct and e is wrong. Also should the words "upon" and "from" be considered in choosing an answer or they interchangeable in this context?</p>