Final answer:
RNA interference can silence a disease-causing gene by d. inhibiting the expression of specific genes through the use of siRNAs or miRNAs that bind to and either degrade or inhibit the translation of the target mRNA.
Step-by-step explanation:
RNA Interference and Gene Silencing
RNA interference (RNAi) is a natural cellular mechanism that silences the expression of specific genes. This process involves the use of small interfering RNAs (siRNAs) or microRNAs (miRNAs) that are either completely or mostly complementary to the mRNA transcript of the target gene. These molecules, after being processed by enzymes such as DICER, become part of the RNA-induced silencing complex (RISC) which binds to the target mRNA. Depending on the degree of complementarity, the binding of the siRNA-RISC or miRNA-RISC to mRNA either results in the cleavage and degradation of mRNA or inhibits its translation, respectively, thus preventing the synthesis of disease-causing proteins.
So, to answer the student's question, RNA interference can silence a disease-causing gene because it inhibits the expression of specific genes (Option d), rather than replacing the gene or amplifying its effect.