Answer:
a. a very cold ecosystem, because they would lose too much body heat
Explanation:
<em>Ectotherms would be l</em><em>east common in very cold ecosystem, because they would lose too much body heat.</em>
Generally, ectotherms are organisms whose internal physiological temperature requirement depends on external sources. They generate very little heat internally and as such, rely on heat sources in the environment for the necessary physiological heat for their bodies.
Consequently, ectotherms live in environments where temperature are more or less constant or constantly seek out external sources of heat for their bodies.
<u>In a very cold environment, the opportunity to seek out external source of heat would not be possible for ectotherms, and body heat would be lost to the environment in the process of maintaining constant body temperature. Hence, they are least likely to occupy this kind of environment.</u>
<em>The correct option is </em><em>a.</em>