Step 1: Use the verse order.
Yoga Sutra 2.32 lists the Niyamas as: sauca, santosa, tapah, svadhyaya, isvara-pranidhana. We simply map the letters on this verse.
Step 2: Find the first one.
Sauca is A. Options 3 and 4 start with B and C, so they are removed.
Step 3: Compare options 1 and 2.
Both start with A. They differ in the second place. Option 1 puts B (Tapas) second. Option 2 puts D (Santosa) second.
Step 4: Decide the second place.
The verse puts santosa straight after sauca, before tapas. So D comes second and option 1 is wrong.
Step 5: Confirm the rest.
Option 2 then has B (Tapas) and C (Svadhyaya), which matches the verse order. All four places agree.
Final Answer:
Option 2 follows the Yoga Sutra order of the observances.
\[ \boxed{\text{Option 2}} \]