Question

plant roots directly obtain water from
precipitation
groundwater stored below the soil
water vapor
water runoff from rivers and streams

Explanation:

Plant roots absorb water from the soil - water which is part of the groundwater stored below the soil surface. Precipitation first has to reach the soil for roots to access it. Water vapor is not a direct source and water runoff from rivers and streams needs to infiltrate the soil first.

Answer:

Groundwater stored below the soil