Help please i keep getting it wrong and it’s difficult

What are some things that limit population growth?

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.

The picture shows a location in india that is very dry and arid. notice the tall mountains in the background; you can find high amounts of vegetation on the other side of the mountains. which statement is most likely true for this area?