Answer: d. formal operational
Choices given in the question are:
a. Latency
b. trust vs. mistrust
c. concrete operational
d. formal operational
Georgie exhibits the major characteristics of a formal operational stage of cognitive development as per Piaget. This stage is characterized by the individual able to think abstractly and understand the form or structures of a problem. Georgie understands that in the experiment, he must combine specific amounts of each ingredient and not just pour in them to create the right mixture