In a scientific investigation, the term "quantitative data" refers to numbers that are usually followed by

a) units

b) graphs

c) writing descriptions

d) photos of measurements

In a scientific investigation, "quantitative data" refers to numbers that are followed by a) units. In quantitative data, exact quantities are used. The remaining options, such as graphs, description writing and photos of measurements tend to describe data in a more qualitative manner, focusing on the data's trend and the general change its shows in their value.