What do Viroids and Virusoids both lack?

Hint: Viroid is a small infectious agents or pathogens that are known to cause disease in plants. The Viroid was discovered in 1971 by T. O Diener. The virus was discovered in 1981 by Randles.

Complete answer:
Viroids and virusoids are different from Viruses. Viroid is composed of single stranded RNA, it has the capacity of self-replication. Virusoids are composed of circular Single stranded RNA, which requires the helper virus to infect the cell.
Viroids consist of a Short single strand of circular RNA, consisting of 246-375 nucleotides. A Viroid genome contains only one molecular spice of RNA. Their molecular weight ranges from 85,000 -1,30,000 Daltons. The Viroids lack the protein coat and its exit has free RNA. The viroids do not contain any protein encoding genes; they are totally dependent on the host for its replication. They are transmitted by cross contamination by mechanical damage to the plant.
Virusoids belong to a large group of infectious agents with low molecular weight. It consists of 220-388 nucleotides. They are referred to as satellite RNA. Virusoids are described as non self -replicating single stranded circular RNA. They depend on helper viruses to replicate and cause infection.

Thus, the correct answer is Viroids and virusoids both lack a protein coat.

Note:
Viroids do not cause disease in humans. They are capable of infecting only the higher plants (Cucumber, potato, tomato, coconut palms). Viroids cause Potato spindle tuber disease and chrysanthemum stunt disease. Virusoids are responsible for causing Human hepatitis D disease.