Which of the following exhibits the highest rate of respiration?

The correct answer is: Germinating seed

Germinating seeds exhibit the highest rate of respiration i.e. the rate of respiration is higher during germination in seeds.

• The respiration rates of vegetative tissues typically decrease from the point of growth to more differentiated regions, while developing buds typically exhibit extremely high respiration rates.
• Since the seeds are alive and require more oxygen for growth, the oxygen consumption rate is higher when the seeds undergo germination.
  
• When a plant tissue is mature, its preparation rate either stays nearly constant or slowly declines as the tissue gets older and eventually experiences senescence.