https://www.gregmat.com/problems/quant?problem=a-student-report-card
There is clearly an error in this question. The second condition should have been framed as having a mean greater than or equal to 16.
Fair, but this is explained below.
“Some students have asked us why the answer is not D - notice that the question says “approximate” - and the minimum value that satisfies the condition is very close to option C.”