Answer:
The correct answer is the alternative because the associative property of the sum states that despite of how the numbers are grouped, the result is not affected
Explanation:
4 + 12+ 18 = (4+12)+18 --> one form to be grouped (note parenthesis) = 4 + (12 +18) --> Second form to be grouped
Hence:
(4+12)+18 = 4+(12+18) (Associative property)