The correct condensed logarithmic expression is ln(xy/z). So option C is correct.
I assume the x term should be part of a natural log, ln(z), due to if it isn't none of the answer choices would be correct.
We can use two logarithmic simplifying rules.
logA + logB = log(A*B)
logA - logB = log(A/B)
Using this, we add ln(x) and ln(y) so xy will be multiplied, while the z will be divided due to it being subtracted.
ln(x) + ln(y)= ln(xy)
ln(xy) - ln(z) = ln(xy/z)