The correct answer among the choices given is option B. The purpose of an expectorant is to liquefy mucous. An expectorant is a drug that aids in the clearance of mucus in the respiratory system. It thins out mucus so it can be expelled from the body easier.
Answer: Development of irrigation systems to provide food for themselves
Explanation:
The Indus River valley achievements could be seen in how they developed their irrigation system to provide food for themselves. Enlisted are the following achievements they made;
1) They developed a uniform weight and measures.
2) They were the first to bring about urban sanitization systems.
3) Transportation and trade was their major goal
4) Their art was highly advanced.
The prices went up super high. It effected the economy greatly. Hope this helped! :)