The correct answer is D,
dose this help?
Answer;
-B3
Explanation;
Refrigerants are divided into two groups according to toxicity:
-Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm; and
-Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm.
They are also divided into three groups according to flammability:
-Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa;
-Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg;
-Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg.
-Therefore; the answer for the above question would be Class B and class 3.
If the membrane of a cell were no longer selectively permeable then "<span>The cell would die as it would not be able to regulate which substances could enter and leave", since a selectively permeable membrane allows both things to enter and leave for the cell's survival. </span>
The electrons are used to generate ATP and its equivalent forms.
