Wrong trigger. We don’t know that there was “no need for scientific assessments” before the ministry responsible for health issues was formed. It’s also not clear that proving assessments are unnecessary would prove that they shouldn’t be issued.

Helps build a bridge from the premises to the conclusion. (B), restated, asserts that if a ministry does NOT have a very strong reason to believe that a scientific assessment is accurate, then it should not issue that assessment. The premises give us reason to think that the Ministry of Health is at risk of producing inaccurate assessments, just as the Ministry of Environment did before. So we have reason to believe that the Ministry of Health doesn’t have “very strong reason” to think its assessments will be accurate. (B), then, allows us conclude that those assessments shouldn’t be issued.

(C) is directed toward telling individuals and organizations not to exert political pressure on government ministries. But we’re trying support a claim about what a government ministry should do, not what individuals/organizations should do.

Leads to the wrong conclusion. (D) allows us to reach a conclusion that a ministry SHOULD issue scientific assessments. But we’re trying to prove that a ministry should NOT issue scientific assessments. (Don’t confuse sufficient conditions and necessary conditions. “If X, then should issue” does not mean “If Not X, then should NOT issue.”)

Leads to the wrong conclusion. (D) allows us to reach a conclusion that the government ministry should resist political pressures. But we’re trying to prove that the ministry shouldn’t issue scientific assessments.