Which of the following statements about change in ecosystems is true? a. ecosystems experience change through human activity only. b. ecosystems experience change through natural events only. c. ecosystems experience no change. d. ecosystems experience change through human activity and natural events.

Ecosystems experience change through human activity and natural events. This is because human activity can impact changes in nature, like climate for example. As a result, ecosystems change in response to the change in nature or natural events, which was caused by human activities. They are interrelated so to speak.  

What are the options?

This is what i did 45-5=4040÷4=10so there are 10 white marbles but am not sure is just a question that am not sure