c选项怎么理解？

问题如下：

Tier 1 capital is used for absorbing losses. Which statement is least accurate about Tier 1 equity capital?

选项：

Investors of the common shares must have a residual claim to the assets.

Among all the components of capital, the Tier 1 equity capital's requirements are the most rigorous.

Tier 1 equity capital must be 4.5% of risk-weighted assets at all times.

The major component of tier 1 equity capital is preferred stock.

解释：

D is correct.

考点：Tier 1 capital

解析：

一级资本中普通股主要由普通股再加上留存收益（而不是优先股）构成，选项D错误。