The ER reportedly contains sensors that monitor the concentration of unfolded or misfolded proteins in the lumen. One proposal suggests that the sensors are normally kept in an inactive state by , particularly .A) molecular chaperones, ribosomes
B) proteasomes, BiP
C) molecular chaperones, BiP
D) enzymes, ER
E) molecular chaperones, RuBisCO

c) molecular chaperones, BIP

Explanation:

BiP is a molecular chaperone found in endoplasmic reticulum's lumen and binds to proteins that are newly synthesized and translocated. By doing this it makes them competent for folding and oligomerization. If this complex is defected it will result is misfolded protein.

C) molecular chaperones, BiP

Explanation:

Molecular chaperones are specific proteins that is responsible for the  folding/assembly or unfolding/disassembly of other molecular structures such as proteins. For example, chaperones help to assemble DNA and folded histones into nucleosomes.

Molecular chaperones include heat- shock proteins (HSPs). An example of a molecular chaperone is binding immunoglobulin protein (BiP)

Binding immunoglobulin protein (BiP) is found in the lumen located in the endoplasmic reticulum (ER). It is found in abundance in all growth conditions, but with an increased synthesis under conditions that result to increased concentration of misfolded or unfolded proteins in the lumen of the ER. In other words, it serves as a sensor to recognize unfolded proteins in the lumen of the ER

Therefore, one proposal suggests that the sensors are normally kept in an inactive state by molecular chaperones particularly BiP