Which of the following sentences is punctuated correctly?
a) Student assistance for tuition is limited when they enter college because there are so many who need the funding: "In 2018, 90% of freshmen used government money to pay for tuition."
b) Student assistance for tuition is limited when they enter college because they: need the funding, and "in 2018, 90% of freshmen used government money to pay for tuition."
c) Student assistance for tuition is limited when they enter college because there are: so many who need the funding, "in 2018, 90% of freshmen used government money to pay for tuition."
d) Student assistance for tuition is limited: when they enter college, because there are so many who need the funding, "in 2018, 90% of freshmen used government money to pay for tuition."