The bottom one is the answer
Answer:

Step-by-step explanation:
In 2x/(x^2 - 1)1/2

Apply the property of natural log
ln x^m = m ln(x) move the exponent before ln


ln(m/n)= ln m - ln n

multiply 1/2 inside the terms

B because i reviewed that with my teacher
It's line2, she replaced 42 with 16 for some reason..