The mode of expression in which a concept, or idea is being conveyed.*1 pointa. Productionb. Techniquesc. Mediumd. Forms

The question asks for the term that describes the mode of expression in which a concept or idea is conveyed. Let's analyze each option:

1. Production: This refers to the process of creating something, but it does not specifically indicate the method of expression.

2. Techniques: While techniques can refer to the methods used in creating a piece of art or communication, it does not directly represent the mode of expression itself.

3. Medium: This term refers to the materials or technologies used to convey an idea, such as paint for a painting, or digital platforms for online content. It reflects how the expression is realized.

4. Forms: This speaks to the structure or shape of the expression but isn't necessarily indicative of the overall method of communication.

Considering these interpretations, the correct answer is c. Medium, as it most accurately captures the concept of the mode of expression used to convey ideas.