Antigen presenting cells (apcs) include macrophages and dendritic cells, which are found in lymphoid tissues and the these are critical in the uptake and presentation of antigen to t cells.

Bcells

Explanation:

An antigen-presenting cell (APC) is an immune cell that detects, engulfs, and informs the adaptive immune response about an infection. When a pathogen is detected, these APCs will phagocytose the pathogen and digest it to form many different fragments of the antigen. Antigen fragments will then be transported to the surface of the APC, where they will serve as an indicator to other immune cells.

The correct answer is- Muscular foot and unsegmented soft body.

Mollusk is the second most diversified phylum ( the first being arthropoda) of animals. Organisms under this phylum are predominantly found in the marine habitats.

The name “mollusca” corresponds to the soft body of the organism ( as the earlieast mollusk is cuttlefish, which is an unshelled organism).

Muscular foot is the locomotory organ of this phylum, which can be contracted and retracted whenever required.

Organisms belonging to this phylum share certain characteristics, including a muscular foot, a visceral mass having internal organs, and a mantle, which may or may not secrete calcareous shell ( that is made up of calcium carbonate).