When there are a number of similar calculations to do, it is convenient to program a calculator or spreadsheet to do them for you. The formula for the volume (V) of a cylinder in terms of height (h) and radius (r) is
... V = π·r²·h
You simply need to substitute the given values and determine if the result is greater than 50. For glass A, this looks like
... V = 3.14·2.25²·3 = 47.68875 . . . . . less than 50, so too small
The volumes of the other glasses are calculated in the attachment.
glass B: large enough
glass C: too small