'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.

RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules. It has gained popularity due to its potential in various fields: 1. It is used in developing gene silencing therapies. This is a core application of RNAi. By targeting specific messenger RNA (mRNA) molecules, RNAi can 'silence' or turn off the expression of particular genes. This has significant therapeutic potential for diseases caused by overexpressed or abnormal genes. 2. It can be used in developing therapies for the treatment of cancer. Many cancers are driven by the overexpression of certain genes or abnormal gene activity. RNAi can be used to silence these oncogenes or genes critical for cancer cell survival and proliferation, making it a promising area for cancer therapy development. 3. It can be used to develop hormone replacement therapies. This statement is incorrect. Hormone replacement therapy (HRT) involves administering hormones (e.g., estrogen, progesterone, testosterone) to replenish deficient levels in the body. RNAi is a gene silencing mechanism and is not directly used for hormone replacement; it affects gene expression, not the direct supply of hormones. 4. It can be used to produce crop plants that are resistant to viral pathogens. This statement is correct. RNAi can be engineered into plants to target specific viral RNA sequences, thereby interfering with the viral replication cycle and making the plants resistant to viral infections. This is a significant application in agricultural biotechnology. Therefore, statements 1, 2, and 4 are correct.