For the first blank, the best transition is:
A. In spite of
For the second blank, the best transition is:
E. In contrast
So the revised sentences would read:
"__________, their fundraising efforts, the marine biology club did not raise enough money to go on a group trip. __________, all of the students were extremely disappointed."
This would effectively convey that despite their efforts (A), they did not achieve their goal (E) and were disappointed as a result.