Which process occurs in the structures that are labeled X?
lactic acid fermentation
alcohol fermentation
glycolysis
Krebs cycle

The process that occurs in the structures marked with X is the Krebs cycle (last option).

Explanation:

The Krebs cycle is a process by which energy in the form of ATP is produced from pyruvate molecules obtained by transformation of glucose, which occurs in the mitochondria, marked with X in the diagram (see image).

The mitochondria is a specialized organelle, whose function is the production of energy within the cell. It has a membrane on the outside that allows the passage of proteins, energetic substrate and ions, and inside it crests are formed where the energetic synthesis takes place.

Learn more:

Krebs cycle link

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .