Agroup of scientists proposes an idea that a chemical compound will enable bean plants to grow faster. they grow one group of bean plants in the presence of the compound and another group in the absence of the compound. then they write up a presentation about the experiment stating that the compound promotes plant growth. which step is missing in their methodology

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.

the answer is c) an oak tree