Answer:
B. 4
Step-by-step explanation:
Based on the genotype of the organism illustrated (TtRr), the organism is a diploid organism i.e. organism with two sets of each chromosome. The number of possible combinations in the gamete can be calculated using the formula; 2^n where n = haploid number
In this case, the organism has a diploid number of 4. This means that the haploid number after meiotic division will be 2. Hence, the number of gene combinations will be 2² = 4 possible combinations.