In Rosenthal and Jacobson's study of teachers' expectations of students identified as "academic bloomers," the authors found that the students identified as "bloomers" improved their test scores over the course of a school year. The researchers concluded that teachers communicated expectation of improvement to "bloomers"

a. by paying more attention to bloomers than they had in the past.
b. by giving them extra help before school.
c. in subtle and complex ways that they could not identify.
d. through the tone of their voice and extra attention.

C.) in subtle and complex ways that they could not identify.

Explanation: The 'bloomers' are students who could be said to come to live after the teachers had identified their potential after careful study and examination. Bloomers are those who from past records or superficial analysis may be considered as ineffective. In Jacob and Rosenthal's study, enhanced expectation placed on students lead to them becoming better performance as the bloomers improved their test scores in the space of just one school year. Leading to to researchers to conclude that the communication of improvement expectation to bloomers was done in a subtle and complex manner they could not identify.

c. in subtle and complex ways that they could not identify.

Explanation:

The word "bloomer" is used to describe a small error that does not have a big impact on anyone's life. Based on this, some teachers called "academic bloomers, those students who had small and harmless learning errors, which were not so serious and could be fixed with time and dedication. For this reason, these teachers used to communicate with these students, showing that they had expectations that they would improve academically. This communication was done in a subtle way and, at times, so complex that the researchers of the study shown above, were unable to identify. However, the communication showed good results, since the " academic bloomers "have improved their test scores over the course of an academic year.

a is the answer because it just is

true