Consider the function f(x)=ax^4 − bx^2 − c, where a,b, and c are real numbers. We are given that f′′(1) = 0 and f′′′(−5) = 12. Find the value of f′(1).
A) f′(1) = −5
B) f′(1) = 0
C) f′(1) = 5
D) f′(1) = 10