Write the Word or Phrase That Best Completes Each Statement $f ( x ) = 32.1 + 1.2 \log ( x + 1 )$

Write the word or phrase that best completes each statement or answers the question.
-Suppose $f ( x ) = 32.1 + 1.2 \log ( x + 1 )$ models salinity of ocean water to depths of 1000 meters at a certain latitude. $x$ is the depth in meters and $f ( x )$ is in grams of salt per kilogram of seawater. Approximate the depth (to the nearest tenth of a meter) where the salinity equals 34 .

A) $37.3 \mathrm {~g} / \mathrm { kg }$
B) $39.3 \mathrm {~g} / \mathrm { kg }$
C) $- 1.0 \mathrm {~g} / \mathrm { kg }$
D) $- 0.9 \mathrm {~g} / \mathrm { kg }$