Please help me with this question!

Question

Find 

Options:

1. Cannot be found
2. ln(x² + 1)
3. (2x)ln(x⁴ + 1)
4. (2x)ln(x⁴ + 1) - ln(5)

Answer 1

By Second Fundamental Theorem of Calculus this derivative f'(x) = ln((x²)² + 1)·(x²)' = (2x)ln(x⁴ + 1).

Answer is 3).