Final Answer:
When sizing a stainless steel crown, it must fit snugly on the prepared tooth and have A) Both mesial and distal contact.
Step-by-step explanation:
Sizing a stainless steel crown involves ensuring a proper fit on the prepared tooth. The correct fit includes both mesial (toward the front) and distal (toward the back) contacts (Option A). The crown should snugly adapt to the tooth structure, providing stability and proper alignment within the dental arch.
Mesial and distal contacts help maintain the position of the crown, preventing any unwanted movement. Options B (Only mesial contact), C (Only distal contact), and D (No contact) do not align with the standard requirement for a well-fitted stainless steel crown on a prepared tooth.
Option A is the answer.