Final answer:
Keratoacanthoma is considered benign with the lowest risk of malignancy compared to basal cell carcinoma, squamous cell carcinoma, and actinic keratosis.
Step-by-step explanation:
The skin condition among the listed options considered to be benign and with the lowest risk of malignancy is keratoacanthoma. Keratoacanthomas are typically benign, grow rapidly, and often resolve on their own, indicative of their low malignancy potential. In contrast, basal cell carcinoma, squamous cell carcinoma, and actinic keratosis carry a higher risk of malignancy. Basal cell carcinoma is the most common form of skin cancer but rarely metastasizes. Squamous cell carcinoma is also unlikely to metastasize and is usually curable surgically if detected early. Actinic keratosis is a pre-cancerous condition that can evolve into squamous cell carcinoma. Therefore, out of the conditions listed, keratoacanthoma has the lowest risk of turning malignant.