The correct answer is option glucose.
The glucose can be used as the immediate source of the energy. The cells can utilize the glucose to form the ATP molecules, which can be used as a source of energy by the body of the organism. The cellulose, chitin, and the glycogen are the polymers, they can only be utilized, once they are broken down into simpler forms.
The chart very nicely lays out the amino acid each codon corresponds to. You're looking for "trp" in the chart, which only appears once, beside the UGG codon. Therefore, only one codon codes for tryptophan.
Water expands as it freezes, so ice generally has more oxygen in it than liquid water, making it denser.
Calcium oxide based on the above explanation is an ionic compound.