Let p, q, and r be the propositions p : Grizzly bears have been seen in the area. q : Hiking is safe on the trail. r : Berries are ripe along the trail. Write these propositions using p, q, and r and logical connectives (including negations). a) Berries are ripe along the trail, but grizzly bears have not been seen in the area. b) Grizzly bears have not been seen in the area and hiking on the trail is safe, but berries are ripe along the trail. c) It is not safe to hike on the trail, but grizzly bears have not been seen in the area and the berries along the trail are ripe. d) Hiking is not safe on the trail whenever grizzly bears have been seen in the area and berries are ripe along the trail.