Typhoons are caused by a. the meeting of storm systems with high mountains. b. wintertime currents of dry, cold air. c. the interaction of ocean currents and monsoon winds. d. an influx of tropical air from the northern mongolian plain.

Typhoons are caused by the interaction of ocean currents and monsoon winds.

Explanation:

The storms that occur in the North West Pacific are called the typhoons. The speed of winds is usually 150 miles per hour or more. If it is greater than that, they are called super typhoons. The heat created by the ocean currents gives considerable amount of energy, when interacted with cold air from monsoon winds, low pressure is created for the typhoon to start. The positive aspect of Typhoons is that they bring fresh water to the surface by decreasing the pollutants in the air and on the earth's surface too.

c. the interaction of ocean currents and monsoon winds.

Explanation:

A typhoon is a violent tropical storm that is found in the northern hemisphere and accounts for about one-third of the annual tropical storm on earth. The name is referred to as the storm that hit the Japanese coasts and needs to the development of the sufficient warm sea surface temperatures, the atmospheric instability and the humidity content in the air. Along with a pre-existing low-pressure system and the like other storm they move to from the west to the northwest and also along the southern chine that is known to have the highest record of the typhoons. They have speeds not exceeding more than 33 knots, while the speed of the violent tropical storm is that of the 105 knots, and occur mostly in the months of the august and the September.

Well, a and b together would be negative. b alone would also be negative.