Step 1: Understanding immunoglobulins.
Antibodies (immunoglobulins) exist in different structural forms such as monomers, dimers, and pentamers depending on their class.
Step 2: Monomeric antibodies.
Monomeric antibodies consist of a single Y-shaped unit. IgG, IgD, and IgE are typically monomeric in structure.
Step 3: Other structural forms.
IgA is usually dimeric in secretions, while IgM is pentameric in blood circulation. This distinguishes them from monomers.
Step 4: Functional significance.
Monomeric antibodies are more flexible and circulate freely in blood and tissues for immune defense.
Step 5: Evaluation of options.
Only option containing all monomeric immunoglobulins is IgD, IgE, and IgG. Other options include dimeric or pentameric forms.
Step 6: Final conclusion.
Thus, monomeric antibodies are IgG, IgD, and IgE.