What chemicals are released to trigger an action potential that diffuses across the synaptic cleft and binds to A. Sodium and potassium lons
B. Dendrites
C.axon
D.neurotransmitters

At a chemical synapse, neurotransmitter is released from the presynaptic element and diffuses across the synaptic cleft. The neurotransmitter binds to a receptor protein and causes a change in the postsynaptic membrane (the PSP).

Explanation:

I am afraid none of the options correspond to what you're looking for. Take a look:

Leukemias: cancer that affects bone marrows.

Lymphomas: cancer that affects lymphocytes (immunity system cells)

Sarcomas: cancer that affects connective and non-epithelial tissue.

There are either 2 options. The question was either typed incorrectly, and you're looking for a cancer type that doesn't affect epithelial tissues (which would be a sarcoma) or you forgot to add one option, which would be:

Carcinomas. Carcinomas are a type of cancer that attacks epithelial tissues, which are found all over the body, which explains why these make up about 90 percent of all cancer cases.

Hope it helped,

BioTeacher101