The first sentence is enough to answer 24. The main verb hold suggests a position, not a theory. Furthermore, the text makes no more mention of human morphology, only human behaviour.
With 26., the closest analogy is (A) although I don't think it's a very useful analogy. The plural countable noun colours matches most closely with details. In the colour spectrum there is a variety of colours, and the inability to name any but the primary colours, suggests a constraint on this variation. Without our rage, fear, greed and love, human behaviour would be more varied.
Student or Learner