Which statement correctly orders the use of FRK and EEMK according to the material?

Which statement correctly orders the use of FRK and EEMK according to the material?

• A. FRK should be used before EEMK
• B. EEMK should be used before FRK
• C. They should be used simultaneously
• D. Not specified

Answer: (A)

The important idea is that these two steps must be done in a specific sequence because one prepares the substrate for the next. FRK serves as the priming step, conditioning the substrate so that it is in the right state for the following modification. EEMK then completes the change on that prepared substrate, so its activity depends on the changes FRK introduced. If EEMK were used first, it wouldn’t encounter the correct substrate state, leading to lower efficiency, more byproducts, or incomplete modification. Doing FRK first also helps keep reaction conditions under control and prevents unwanted interactions between the reagents. The material shows that the finishing modification by EEMK is designed to occur after FRK has created the necessary intermediate, which is why FRK should come before EEMK.

The important idea is that these two steps must be done in a specific sequence because one prepares the substrate for the next. FRK serves as the priming step, conditioning the substrate so that it is in the right state for the following modification. EEMK then completes the change on that prepared substrate, so its activity depends on the changes FRK introduced. If EEMK were used first, it wouldn’t encounter the correct substrate state, leading to lower efficiency, more byproducts, or incomplete modification. Doing FRK first also helps keep reaction conditions under control and prevents unwanted interactions between the reagents. The material shows that the finishing modification by EEMK is designed to occur after FRK has created the necessary intermediate, which is why FRK should come before EEMK.