Final Answer:
Currently, (a) M2 remains less than half of M1 but comprises twice the share of M1 it did in 1960.
Step-by-step explanation:
In 1960, the share of M2 in comparison to M1 can be expressed as M2/M1 = 1/2. This means that M2 constituted half the value of M1 at that time. The current statement implies that the share of M2 has doubled since 1960, making it twice the percentage of M1. Mathematically, this is represented as follows: Current share of M2/M1 = 2 * (M2/M1)_1960, where (M2/M1)_1960 is the share of M2 in 1960. This signifies that while M2 remains less than half of M1, its relative importance has increased over the years.
The mention of "less than half of M1" indicates that M2/M1 < 1. Combining this with the fact that the share of M2 has doubled since 1960 (M2/M1 = 2 * (M2/M1)_1960), we can infer that the current value of M2/M1 is greater than 1. Therefore, option (a) M2 fits the description in the statement. This aligns with the understanding that M2 has increased in significance compared to M1, remaining less than half but now constituting twice the share it did in 1960.
In summary, the answer is (a) M2, as it satisfies the conditions outlined in the statement about the current relationship between M2 and M1 and their historical comparison since 1960.