Determine the first partial derivatives of (h(r, s) = ln(r²s² + 1)) at the point P(4, -1).

a) (2r/(r²s² + 1)), (2s/(r²s² + 1))
b) (2r/(4s² + 1)), (-2s/(r²s² + 1))
c) (8r), (-2s)
d) (ln(8r)), (ln(-2s))