Correct Answer: precious

Solution : The correct choice is the first option.

Explanation:
Precious is the most appropriate synonym for "valuable" because both words convey the idea of something being of great worth, importance, or rarity.
The meanings of the other options are as follows:

• Commonplace: Ordinary and not special.
• Ordinary: Common and not exceptional.
• Cheap: Inexpensive or low in cost.

Therefore, the correct answer is precious.