The Neem tree has acquired industrial importance due to its various properties. Option 3 is correct as it states that the Neem tree is a source of `biofertilizer`, `biopesticide` and `anti-fertility` compound.

`Biofertilizer` refers to a substance which contains living microorganisms that, when applied to seeds or soil, colonize the rhizosphere and benefits the plant by increasing the supply of primary nutrients. Neem helps with the growth of beneficial soil microorganisms, making it a good biofertilizer.

`Anti-fertility compound` refers to a substance that reduces or eliminates fertility. Indirectly, neem products have anti-fertility effects as they can work as effective contraceptives.

`Biopesticide` refers to pesticides derived from natural materials such as animals, plants, bacteria, and certain minerals. The compounds in neem leaves and seeds show properties of a natural, non-toxic pesticide.

Options 1, 2, and 4 mention `anti-cancer drug` which is incorrect because there`s no conclusive scientific evidence to prove that Neem has anti-cancer properties. Even though it is used in some natural treatments, it’s not recognized as a cure or a prevention for cancer.