For these should a correlated or independent sample t test be used? (d) Forty students taking general psychology are randomly assigned to either treatment A or B and Ho= Ua - Ub = 0 is tested. (e)...

For these should a correlated or independent sample t test be used?

(d) Forty students taking general psychology are randomly
assigned to either treatment A or B and  Ho= Ua - Ub = 0 is
tested.
(e) Delayed posttest achievement scores were compared with
immediate posttest scores for all participants. (e
(f) Grade-equivalent scores in reading were compared with
grade-equivalent scores in math for 100 special education
students.