Final answer:
The type of receptor that slowly adapts and is activated when the skin is between warm and cold temperatures is likely a Ruffini ending, which is a type of thermoreceptor.
Step-by-step explanation:
To match the type of receptor with the appropriate description regarding skin sensation, we need to consider which receptors are activated when the skin is between warm and cold temperatures and which adapt slowly. The thermoreceptors are specialized sensory receptors that respond to temperature changes. Since Ruffini endings are slowly adapting, encapsulated receptors that detect skin stretch, joint activity, and warmth, they are most likely the receptors in question here. Thus, these receptors that slowly adapt and would be activated by moderate temperatures are most likely Ruffini endings, which fall under the classification of thermoreceptors.