Final answer:
RNA interference (RNAi) is triggered by foreign, double-stranded RNA (E). The siRNAs produced from dsRNA guide the degradation or silencing of the complementary foreign mRNA, preventing translation and protein synthesis.
Step-by-step explanation:
The type of molecule that triggers RNA interference (RNAi) is E. foreign, double-stranded RNA. RNAi is a biological process where double-stranded RNA (dsRNA) is cut into small interfering RNAs (siRNAs) by an enzyme called DICER.
These siRNAs then combine with RNAi Induced Silencing Complex (RISC), and the antisense strand of the siRNA within the complex binds to complementary sequences in foreign mRNA, targeting them for degradation. This process is a defense mechanism against viruses that produce dsRNAs during their replication cycle and can also be used to regulate gene expression more broadly.