What are the differences between internal receptors and cell-surface receptors?

Internal receptor: Internal receptors present on the cytoplasm, and also known as cytoplasmic or intracellular receptor. These Internal receptors respond to hydrophobic ligand molecules which can travel across the plasma membrane. These receptors can influence (directly) the gene expression means how much a specific protein is produced from a gene without having to pass the signal on the other receptor.

Cell-surface receptor: cell-surface receptor is present on the cell membrane is known as trans-membrane receptors. This trans-membrane receptor binds to external ligand molecules which cannot travel across the cell membrane. They are also called cell-specific proteins because they are specific to individual cell type. The cell-surface receptor has 3 main components:

1) External ligand-binding domain.

2) Hydrophobic membrane-spanning region.

3) Intracellular domain.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.

looks like the answer is     c     to me!