Context: The following passage describes the effects of a gene mutation, which is a permanent change in a gene. Read the passage and then follow the instructions below.

A pea plant's height is affected by substances that are made inside the plant's cells. One of these substances is called gibberellin.
Gibberellin is made in a pea plant's cells by a protein called GA 3-oxidase. The GA 3-oxidase protein is encoded by the LH gene.
A certain pea plant had a mutation in its LH gene. Compared to the LH gene without a mutation, the mutated LH gene encoded a form of the GA 3-oxidase protein with a different structure.
This different form of the GA 3-oxidase protein could make only a small amount of gibberellin. The plant with the mutation grew to a shorter height than pea plants containing more gibberellin.
Figure: pea plants with different amounts of gibberellin.
Complete the sentence.
The mutation in the () affected the structure and function of the ().
A. GA 3-oxidase protein . . . LH gene
B. LH gene . . . GA 3-oxidase protein
Select the correct answer from the given choices and respond with the letter of the chosen option.

B