'RNA interference (RNAi)' technology has gained popularity in the last few years. Why?1.It is used in developing gene silencing therapies.2.It can be used in developing therapies for the treatment of cancer.3.It can be used to develop hormone replacement therapies.4.It can be used to produce crop plants that are resistant to viral pathogens.Select the correct answer using the code given below

1. A

   1, 2 and 4

   (a) 1, 2 and 4. RNAi silences genes (including viral and oncogenes) and has been used to engineer virus-resistant crops (for example papaya ringspot via gene silencing). Hormone replacement therapy is not an RNAi use. That trio is the official key.

2. B

   2 and 3

   (b) 2 and 3. Statement 3 is false; dropping 1 and 4 is wrong. Not the key.

3. C

   1 and 3

   (c) 1 and 3. Statement 3 is false. Not the key.

4. D

   1 and 4 only

   (d) 1 and 4 only. Statement 2 is also true: RNAi is explored in cancer therapy. Dropping 2 is not the key.

Summary. Official key is (a). RNA interference knocks down complementary mRNA. That is gene-silencing therapy, including oncology pipelines, and a plant-virus resistance tool. It does not replace hormones. Honour (a).