When you use procedures like placebos and double-blind conditions, you are attempting to set up __________ for factors that would make your experimental findings questionable

According to research:

a. a person will get more help in a crowd. b. there is safety in numbers. c. the fewer people present, the greater chance of receiving help. d. people are not altruistic.

Children make the transition from Piaget's preoperational stage to the stage of concrete operations about age 5 to 7

Indicate whether the statement is true or false