Hey there!
The correct answer to your question is the 1st option.
To have more resources in the future, we must conserve resources today.
Conserve means to protect, maintain, or save. If we save resources then that will help us have more in the future. It will not be 2 because wasting resources will leave none for the future, and it will not be 3 since using is similar to wasting.
Hope this helps you.
Have a great day!