Final answer:
Mutations in the d) BRCA1 and BRCA2 genes are found in at least half of inherited breast cancers. Hence, d) is correct.
Step-by-step explanation:
Mutations in the BRCA1 and BRCA2 genes are found in at least half of inherited breast cancers. These genes are responsible for producing proteins that help repair damaged DNA and maintain the stability of the cell's genetic material.
When these genes are mutated, the proteins they produce function poorly and DNA in the affected cells is not efficiently repaired, leading to an increased risk of breast cancer.