Identify the biotic factor of an ecosystem from the following: a. soil composition b. trees c. temperature d. sunlight

The correct answer is:  [B]:  "trees" .

Note:  Answer choices:  [A]:  "soil composition";  
                                         [C]:  "temperature" ;
                                         [D]:  "sunlight" ; 

                                       are incorrect because these are "ABIOTIC" (i.e. physical, non-living) factors of an ecosystem.

The correct answer choice is:  [B]:  "trees". 

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city. 

The answer is d., a mountain.