Question

16. True-breeding plants
a. produce the same offspring when crossed for many generations.
b. result from a monohybrid cross.
c. result from a dihybrid cross.
d. result from crossing over during prophase I of meiosis.

Answer 1

Just remember that True-breeding means that time and time after pollination it will result in the same genotype and phenotype.
Here is somewhat a better explanation. A plant, that when self-fertilized, only produces offspring with the same traits. The alleles for these type of plants are homozygous.

For example, the gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). A true-breeding round seed plant would be (RR) for that trait and a true-breeding wrinkled seed plant would be (rr).