Step 1: Understanding Plato's theory of knowledge.
Plato's epistemology is based on his theory of forms and the hierarchy of knowledge:
- Conjecture (A): This is the lowest form of knowledge, dealing with mere opinions or guesses.
- Discursive Intellect (B): This form involves reasoning and the use of rational thought to understand the world of forms.
- Belief (C): This lies above conjecture and involves belief in the physical world but is still based on perception.
- Rational Insights (D): This is the highest form of knowledge, involving direct knowledge of the forms through philosophical reasoning.
Step 2: Conclusion.
The correct sequence is from Conjecture to Rational Insights, hence the correct answer is 1. A, B, C, D.
Final Answer:
\[
\boxed{\text{The correct answer is 1. A, B, C, D.}}
\]