Context: In a group of Labrador retrievers, some individuals have black fur and others have brown fur. In this group, the gene for the fur color trait has two alleles. The allele for black fur (F) is dominant over the allele for brown fur (f).
This Punnett square shows a cross between two Labrador retrievers.
What is the probability that a Labrador retriever produced by this cross will be heterozygous for the fur color gene?
A. 3/4
B. 2/4
C. 4/4
D. 0/4
E. 1/4
Select the correct answer from the given choices and respond with the letter of the chosen option.

C