Mr. Grant is a reflective teacher who is always trying to improve his teaching practices to increase student learning. He has conducted several research projects and changed teaching strategies on the basis of the results. In his latest reflections, he predicted that his low-achieving students would complete their spelling tasks in less time and score higher on spelling tests if he began using a buddy system. In the research cycle, Mr. Grant has developed:.

a hypothesis                  

Explanation:

Hypothesis: In statistics or research methods, the term "hypothesis" is described as an explanation or an idea that an investigator or a researcher can test through experimentation and study. A hypothesis is referred to as a guess or a theory outside science.

In other words, a hypothesis is determined as something which is considered as less than a well-established theory but more than a wild guess.

In the question above, Mr Grant has developed a hypothesis.

its b i googled it wish u luck

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."