Joanne always attempts to discipline her child through grounding because it has worked in the past. Lately, it has not been working, but she keeps trying because it always worked before. Joanne has encountered which obstacle to problem solving?

Mental set

Explanation:

mental set: is a tendency to approach situations the same way because that way worked in the past. For example, a child may enter a store by pushing a door open.

A mental set is a tendency to only see solutions that have worked in the past. This type of fixed thinking can make it difficult to come up with solutions and can impede the problem-solving process.

Mental Set

Explanation:

Mental set is a problem solving approach in which the idea of what worked in the past is still being used. That is, Joanne has set her mind on disciplining her child through grounding because this method has worked in the past. This is the obstacle that Joanne is facing, and instead of changing her approach, she sticks to what she knows even though the result is not forth coming like before.

because he had a big bear belly

i would say b. research typically uses a variety of sources