Concept:
Dental hygiene refers to the care and maintenance of oral health, especially the cleanliness of teeth and gums. Common dental terms include teeth, plaque, and calculus.
Dental calculus refers to hardened plaque deposits that accumulate on teeth and may lead to oral diseases if not removed.
Step 1: Identify terms related to dental hygiene.
Among the given options:
\[
\text{Teeth}
\]
and
\[
\text{Calculus}
\]
are directly associated with dental hygiene.
Step 2: Eliminate unrelated terms.
• Red Cross is a humanitarian organization.
• Esophagus belongs to the digestive system.
• Pancreas is a digestive and endocrine organ.
Step 3: Choose the correct combination.
Thus, the correct set is:
\[
B, C
\]
Hence, the correct answer is:
\[
\boxed{(B)\ B, C\ \text{only}}
\]