The answer is option B "temperature." Greenhouse effect is the process of trapping the suns heat in the lower atmosphere. A increase of greenhouse effect would cause surface temperatures to rise. Which then contributes to global warming because of melting the ice bergs in cooler areas on Earth and causing waters to rise and creating storms. It's not option A because the sun gives off heat or harmful radiant waves which doesn't increase carbon dioxide levels. Wouldn't be option D because it would contribute but it wouldn't happen without a increase of temperature. It also wouldn't be option C because oxygen isn't relevant in this case.
Hope this helps.
<span>The discovery of thornless plants was made around the turn of the 20th century. To name one such thornless plant, particularly, the Blackberry plant, the deviation from the thorned blackberry canes were discovered in the United States. Since then, several different thornless blackberry varieties have been cultivated for fruit gardens.</span>
Below are the 6 reasons a bone must be continually remodeled:
1.new cancellous bone must be remodeled into compact bone tissue.
2.bones increase and decrease in mass based on the stress they experience.
3.reshape the bone.
4.rapair the bone.
5.remodeled to replace worn collagen and hydroxyapatite.
<span>6.regualate calcium levels in the blood.</span>
Hydrogen, for example, it gives trees inter molecular force.