Answer:
A
Step-by-step explanation:
Since square pyramids A and B are similar, they need to have similar lengths.
Pyramid B's lengths are 2 times larger than that of pyramid A.
Pyramid A: 16 units, 16 units, 20 units.
*2 *2 *2
Pyramid B: 32 units, 32 units, ? units
So, the missing side length has to be 20 *2 = 40 units.
Please mark as brainliest!