In Recent Years, What Has Been the Trend Regarding the Relationship

In recent years, what has been the trend regarding the relationship between political parties and health legislation?

A) Policy positions of the major parties have become very predictable and more inflexible.
B) No major political parties have shown particular interest in health legislation since the late 1980s.
C) Parties have become weaker than in the past, and thus less able to control their members' policies.
D) Cooperation between parties is the norm, rather than the exception, when it comes to health legislation.