The correct answer is 1 and 3 only. Azadirachta indica is commonly known as neem tree. It is a tree in the mahogany family Meliaceae. Neem Tree can grow up to 30 m tall and 2.5 m in girth. The roots penetrate the soil deeply, at least where the site permits, and, particularly when injured, they produce suckers. The tree is easily propagated - both sexually and vegetatively. It can be planted using seeds, seedlings, saplings, root suckers, or tissue culture. Neem leaf has various properties such as antibacterial, antiviral, antiparasitic, anti-inflammatory, anticarcinogenic, antioxidant, and immune upregulation. It is used in the pharmaceutical industry. Hence statement 3 is correct. Neem oil can be used as a pesticide to control the proliferation of some species of insects and mites. Hence statement 1 is correct. It is also used for skin diseases and digestive system disorders. Neem Oil can also be obtained from solvent extraction of the neem seed and this solvent-extracted oil is mostly used for soap manufacturing. Neem oil can be used as a pesticide to control the proliferation of some species of insects and mites. Neem seeds are used in the manufacture of biofuels and hospital detergents (not any particular source). Hence statement 2 is not correct. (According to UPSC Official Answer key)