Answer:
c. Instrumentation
Explanation:
In research methods and statistics, mainly there are eight different types of threats associated with the internal validity including experimental mortality, regression, interaction of threats, selection, history, testing, maturation, and instrumentation.
Instrumentation: The term "instrumentation" is described as one of the different types of internal validity threat that encompasses the change in the scores, instruments, or observers that may produce a few changes in the outcomes of a particular study.
In the question above, the given statement represents "instrumentation".
The current president of India is Pranab Mukherjee, a Bengali politician from the Indian National Congress. He came to this office in 2012.
<span>The sun has six layers. Three layers, the corona, chromosphere and photosphere, comprise the sun's atmosphere or outer layer. The other three layers, convective zone, radiative zone and core, comprise the inner layers, or the parts of the sun that are not seen. <span>Fusion is the process that powers the sun and the stars.</span></span>
