Answer: option a.
Step-by-step explanation:
To solve the given exercise nad write the expression as a single logarithm, you must keep on mind the following properties:
[tex]ln(a)+ln(b)=ln(ab)\\m*ln(a)=ln(a)^m[/tex]
Therefore, by applying the properties shown above, you can rewrite the expression given, as following:
[tex]lnx^{2}+3lny=lnx^2+lny^3=ln(x^2y^3)[/tex]
Then, the answer is the option a.