The ceiling function, denoted by ⌈x⌉, gives the smallest integer that is greater than or equal to x. Therefore, ⌈-0.75⌉ is the smallest integer that is greater than or equal to -0.75.
Since -1 is the smallest integer that is greater than or equal to -0.75, we have:
⌈-0.75⌉ = -1
Therefore, the functional value for the ceiling function at -0.75 is -1.
The answer is option A.