B is correct. Krypton is a noble gas which has a full outer shell of 8 electrons and is generally unreactive because of it.
Beneficence is the practice of offering selfless help to others. Medical and health practitioners are called upon by ethicists to uphold a high degree of commitment to helping other, and refraining from causing harms to others as well as rescuing their patients if they are in dire need of their special skills in treatment and medicine. the practitioners are expected to adhere to acts that brings more benefit to people, their patient and society at large.
The best answer in this case is C, "the researchers applied creativity to solve a problem in running an experiment".
Distributing the computing load across the global community by sharing processing power is a creative response to tackle the challenge in simulating protein folding for the experiment. This does not change or reduce the scientific merits of the experiment, so we can discount the first two answers (a & b). Answer d talks about well established scientific techniques, although the question wasn't really centered around the specific techniques, so it's not as relevant an answer as C.
The answer to this question would be: increased food height
Giraffe becomes tall because its food height is increased. In this case, the environmental pressure on Giraffe would be the increased height of the food.
The taller giraffe has access to higher food. Then, the giraffe with the higher chance of survival in this scenario would be the giraffe with a taller height.
A leaf is made up of many layers and is surrounded by two. Upper epidermis, mesophyll, bundle sheath, vein, mesophyll, lower epidermis, and guard cells.