<span>I’ve answered this
question before so if these are the choices to the question presented:
An oxygen atom double-bonded to a carbon atom, with a hydrogen atom
single-bonded to the same carbon atom. </span><span>
<span>A hydrogen atom covalently bonded to an oxygen atom, which is
covalently bonded to a carbon in the carbon chain. </span>
<span>A carbon atom single-bonded between two other carbon atoms,
with an oxygen atom double-bonded to the central carbon atom as well. </span>
<span>An oxygen atom single-bonded between two carbon atoms within
a carbon chain.
Then, the answer would be “a hydrogen atom covalently bonded to an oxygen atom,
which is covalently bonded to a carbon in the carbon chain.<span>”</span></span></span>
You have to start listing from the bottom :
3. Secondary Consumers
2. Primary Consumers
1. Producer
