In a experiment, a person was subjected to perform 90 minutes leg extension exercise once a day for five days. Every day only the left leg was exercised while other was kept at rest. on the fifth day, concentrations of different mRNAs were measured from muscles of both legs, towards the end of the exercise session. Three major types of mRNAs, P, Q and R were found to show distinct variations in levels:

The following are the possible genes from which these mRNAs are synthesised; 

I. Gene responsible to initiate cell division 

II. Stress response gene 

III. Mitochondrial protein synthesis gene 

IV. Metabolic priority gene P, Q and R respectively must be for mRNAs of 

(a) II, IV and III 

(b) I, II and IV 

(c) II, IV and I 

(d) IV, II and I