The steady state level of a plant metabolite 'M' is determined by the complex interplay of its biosynthesis, catabolism and transport processes from the source to the sink organ. A researcher tested following molecular and genetic strategies for engineering the metabolite 'M' in the native host plant.

A. Increasing catalytic efficiency of its rate-limiting biosynthetic enzyme in the source organ.

B. Increasing catalytic efficiency of the catabolic enzymes in the source organ.

C. Generating knock-out of the transporter protein in the source organ.

D. Repression of the catabolic enzymes in the sink organ.

Which of the above-mentioned strategies will provide a higher accumulation of the target metabolite 'M' in the sink organ?