A particular mountain stream is home to a population of salamanders that are red in color. In the past year, a second population of salamanders that are dark blue in color
moved into the same stream. Scientists researching the stream have recently discovered young salamanders that are red with dark blue patches on their bodies.
What can the scientists conclude from this evidence?
A). The salamanders are suffering from a bacterial disease.
B)..The salamanders are on the verge of becoming extinct.
C). The salamanders undergo asexual reproduction.
D). The salamanders undergo sexual reproduction.

D

Explanation:

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

the answer is b. dilution