What could be the main reason for strengthening water quality standards?a. human health issuesb. natural animal issuesc. industrial issuesd. all of the above

The main reason for strengthening water quality standards could be "d. all of the above". This is because:

a. Human health issues: Poor water quality can lead to diseases such as cholera, diarrhea, dysentery, hepatitis A, typhoid, and polio. It's essential to have clean water to prevent these health issues.

b. Natural animal issues: Animals also depend on water for survival. If the water quality is poor, it can affect their health and disrupt the ecosystem balance.

c. Industrial issues: Industries often discharge waste into water bodies, which can lead to water pollution. Strengthening water quality standards can help regulate these discharges and prevent pollution.

Therefore, all these factors contribute to the need for strengthening water quality standards.