The correct answer is option 4, Worms. Worms are known to multiply very slowly in comparison to bacteria, viruses, and fungi.

Option 1: Bacteria - Bacteria generally have a high rate of multiplication. They can reproduce rapidly through binary fission, where the parent cell divides into two identical daughter cells.

Option 2: Virus - Viruses are known for their ability to rapidly multiply inside host cells. Once they infect a host cell, they take over the cell`s machinery to produce more virus particles.

Option 3: Fungi - Fungi can reproduce through various methods, including spore production and cell division. While they may not multiply as rapidly as bacteria or viruses, they still have a faster multiplication rate compared to worms.

Option 4: Worms - Worms, including earthworms and parasitic worms, have a relatively slow multiplication rate. They reproduce sexually, and their reproductive cycles are often longer compared to bacteria, viruses, and fungi.

In summary, while all the options listed are capable of reproduction, worms typically multiply at a significantly slower rate compared to bacteria, viruses, and fungi.