To avoid the ecological issues, scientists and government agencies consider how sustainable development_________

The blank in the sentence should be filled by a verb that conveys influence. 

Affects (Option B) is the correct verb here, meaning "has an impact on".

Effects (Option A) is a noun, not a verb, so it's grammatically incorrect. 'Is affective' (Option C) is inaccurate, as affective relates to emotions, which doesn't fit here. Is affectionate (Option D) is also incorrect, as affectionate means loving or fond, which is unrelated to the context of sustainable development.