Answer:
Option C. is correct.
Explanation:
According to Chargaff's rules, DNA (Deoxyribonucleic Acid) from any species of an organism should have purine and pyrimidine bases in the ratio 
This ratio is very important for solving the structure of DNA.
As per this rule, DNA is double-stranded, and covalent bonds between identical nucleotides hold the strands together.
So, Option C. is correct.
Answer;
These are telltale signs that Valerie is suffering from Heat exhaustion.
Explanation;
Heat exhaustion is a part of heat related illnesses that begin with heat cramps, progresses to heat exhaustion, and finally to heat stroke.
The body cools itself by heavy sweating and allowing that sweat to evaporate.
Heat exhaustion symptoms include excessive thirst, headache, weakness, nausea, vomiting, dizziness, muscle cramps and a weak, rapid pulse.
30 to 40.
Hope this helps !
Photon
