The correct answer is: C. market line
The market line is a graph that shows the relationship between risk and return for a portfolio of stocks. It is a straight line that goes through the origin, and it represents the best possible trade-off between risk and return.
A dashed line is a line that is not continuous. It is often used to represent a trend or a relationship that is not perfectly linear.
A straight line is a line that has no curves. It is the simplest type of line, and it is often used to represent a simple relationship between two variables.
A risk line is a line that represents the level of risk associated with a particular investment. It is often used to compare the risk of different investments.
In conclusion, the market line is the correct answer because it is a straight line that goes through the origin and represents the best possible trade-off between risk and return.