The verbs moods which would be best to combine in such an essay are:
C. the conditional and subjunctive moods.
Explanation:
The essay is about what life would be like if all wars were ended. Notice that this is a hypothetical essay. It is not about reality, not about what is, but about what could be. First, there is a condition that must be met: "if all wars were ended". To express such an idea - just like the sentence itself did -, we need the conditional mood. After establishing the condition, we can start talking about possibilities and wishes. That is what the subjunctive mood is for. Therefore, an essay that has such a theme would most likely combine the conditional and subjunctive moods.
Standing water is not good for the environment so it needs to be vanished and shall no longer be around humans or animals that can catch the deadly disease malaria !
Using cool colors such as purple blue etc in an artpiece would set a dark sad gloomy mood rather than an artpeice with warm tones such as yellow red orange etc makes you feel happy and cheerful.
