Radiometric dating of a sedimentary rock sample shows an age of 1.5 million years. What conclusions can be drawn from this data? Radiometric dating cannot be used on sedimentary rock so no conclusions can be drawn.
The rock is a minimum of 1.5 million years old but it may be older.
The rock is a maximum of 1.5 million years old but it may be younger.
The rock is exactly 1.5 million years old.

I believe, The rock is a minimum of 1.5 million years old but it may be older

Explanation:

Gradpoint

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.