Final answer:
The area of individual competence that is most lacking in the scenario is effective listening. Therefore, the correct option is c) Effective listening.
Step-by-step explanation:
In this scenario, the area of individual competence that is most lacking is c) Effective listening. Ellen's response indicates a lack of effective listening skills because she immediately dismisses Alex's idea without fully considering it or engaging in a constructive conversation about potential drawbacks. Effective listening involves actively paying attention and considering others' perspectives before forming a judgment. In this case, Ellen's response hinders productive discussion and problem-solving within the group.