Which signal are you talking about?
The correct answer is: Layer 1, layer 2, and layer 4 in all three regions.
The index fossils are fossils that are commonly used for identifying a geological period of time, and these fossils are also very wide spread, as well as having a rapid evolutionary trends.
By this picture, we can easily see that even though we have rock strata from different regions, the same layers contain the same fossil, and it is a fossil that also is rapidly evolving so has a minor change in each layer.
Answer: a) it states that sugar is the chief ingredient in the juice.
Explanation: In food labels, ingredients are listed in descending order, that ingredient present in high quantity is listed first and this ingredient is the main ingredient.