Decide whether integration by parts or substitution should be used to compute the indefinite integral

cos(lnx)/x dx

If substitution, indicate the value of u; if by parts, indicate f(x) and g(x).

A) integration by parts; f(x) = cos(ln x), g(x) = 1/x

B) substitution; u = ln x

C) substitution; u = ln x /x

D) integration by parts; f(x) = 1, g(x) = cos(ln x)/ x

E) none of these