From one trophic level to the next, only_(a) % of the energy is transferred. The other (b)___% is used by the organisms getting consumed during its life processes.
A. (a) 25, (b) 75
B. (a) 10, (b) 90
C. (a) 75, (b) 25
D. (a) 90, (b) 10

B. (a) 10, (b) 90

Explanation:

The ecosystem consists of a flow of energy that unidirectional and there is always a decrease in the amount of energy when it's transferred from one place to another. Such as in the food chain there is a transfer of 10% amount of energy which is used by the various organisms and 90% of energy is lost between the tropic levels in form of heat and respiration.

Carbon-14 has a half-life of 5,730 years and most igneous rock is older than that.

Iam not sure but to me it with be a or dsorry if i was late! hope this ! : )if you really want me to find out the answer that is correct tell me and i will do more research but the a or d makes sense to me.