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

1. Correct. RNA interference is a natural gene-silencing mechanism using small RNA molecules (siRNA/miRNA), so it is directly used in developing gene-silencing therapies.

2. Correct. RNAi can silence oncogenes or other cancer-related genes, so it has been explored for cancer therapeutics.

3. Incorrect. Hormone replacement therapy means supplying deficient hormones externally; RNAi does not replace hormones, it mainly suppresses gene expression.

4. Correct. RNAi has been used to create virus-resistant crop plants by silencing viral genes or essential host factors needed by the virus.

Hence, 1, 2 and 4 are correct.