What data might strengthen the connection between DDT and robin populations?
​

Biomagnification of DDT leads to an increase in its concentration at the higher trophic level and its higher concentration in birds leads to the disturbance in their calcium metabolism. ... In this way, the biomagnification of DDT leads to a decrease in the bird population.

Explanation:

the third answer is correct (c).

the laws that regulate the financing of political campaigns seek to guarantee the smoothness of funding so that there is no abuse of electoral economic power and to avoid the capture of future politicians by the donors.

this is because donor agents have their private interests that are not necessarily the same interests of the society that elected politicians must defend.

thus, interest groups should seek their interests within the legality of lobbying practices that are regulated.