C is correct. the rest is either about food webs or about both food webs and food chains.
Explanation:
Option 1.
4y=12
Dividing 4 both sides
y=3
Division property should be used.
Option 2.

Cross multiplying each other,
y=12(4)
y=48
Option 3.
2(4y)=12
Opening bracktet in LHS
8y=12
Dividing both sides by 8 i.e.

Division property is used.
Option 4.
y+4=12
Subtracting both sides by 4 i.e.
Y+4-4=12-4
y=8
Subtraction property is used.
<em><u>It means that in option (4) Soo-Jung used the subtraction property of equality to solve an equation for y.</u></em>
Which signal are you talking about?
I don't know if this helps or not but you would want to know the age of the rock (absolute dating) and from there you will be able to know the age of the fossil and what caused it to die.
Answer:
temporal reproductive isolation
Explanation:
The correct answer would be temporal reproductive isolation.
<u>Reproductive isolation</u> generally refers to series of biological mechanisms or processes that prevent members of different species from mating/fertilization or prevent the product of their mating to be invalid.
Some reproductive isolation processes prevent members of different species from mating or prevent fertilization as a result of mating. These processes are known as pre-zygotic reproductive isolation mechanisms.
Some other processes ensure that the product of fertilization (when it occurs) is invalid. These are known as post-zygotic isolation mechanisms.
<em>A good example of the pre-zygotic reproductive isolation process is </em><em>when closely related by different species bloom at different times</em><em>. This will prevent mating or cross-pollination to happen between the different species. This is known as temporal reproductive isolation.</em>