Which feature is essential for ensuring content is perceivable by users with visual impairments?

The essential feature for ensuring that content is perceivable by users with visual impairments includes all the options provided, which is why the answer is all of the above.

Large font sizes enhance readability by making text easier for individuals with low vision to see. High color contrast between text and background helps users distinguish content more clearly, especially for those who have certain types of visual impairments, allowing them to read information without strain. Text descriptions for visuals, also known as alt text, provide crucial context to users who cannot perceive images. These descriptions enable screen readers to convey the content and meaning of images to users who rely on auditory output.

Each of these features addresses a different aspect of accessibility, and together, they create a more inclusive experience for users with various levels of visual impairment. Focusing on only one of these features would leave gaps in accessibility, highlighting the importance of an integrated approach where multiple methods work in unison to support all users.