Based on the climate data provided, the most accurate conclusion is:
B. locations by the ocean typically do not get as cold in the winter or as hot in the summer as locations that are located inland.
This conclusion is supported by the data, which shows that Eureka, located by the ocean, has milder temperatures both in winter (with average lows not dropping as low as those in Redding) and in summer (with average highs significantly lower than those in Redding).