The correct answer is "37 + 54".

Solution:
To find the correct answer, we find the sum of each expression by rounding (up or down) the addends.

At Option A:
Round the addends to the nearest tens and then add.

64  +  57  =  ?
↓          ↓
60  +  60  =  120

This expression has a sum nearly equal to 120.

At Option B:

32  +  55  =  ?
↓           ↓
30  +  60  =  90

This expression has a sum nearly equal to 90.

At option C:

37  +  54  =  ?
↓          ↓
40  +  50  =  90

This expression has a sum nearly equal to 90.

At the last option D:

15  +  84  =  ?
↓          ↓
20  +  80  =  100

This expression has a sum nearly equal to 100.

So, the desired answer is "37 + 54".