_____ is an instruction format that illustrates a task using pictures.

a A flowchart

b A diagram

c A paragraph

d An if-then table

b A diagram

b. A diagram

The answer is b) A diagram.

To arrive at this answer, we need to understand the given options and determine the best fit for an instruction format that uses pictures. Let's examine each option:

a) A flowchart: A flowchart is a visual representation of a process or algorithm, which uses various shapes and arrows to illustrate the flow of steps or decisions. While it does use visual elements, it primarily focuses on representing the logical flow rather than providing specific instructions using pictures.

b) A diagram: A diagram is a visual representation that uses pictures, shapes, and symbols to illustrate a concept or task. It can convey information or instructions through visual elements rather than relying solely on text-based descriptions. This option seems to be the most fitting for an instruction format using pictures.

c) A paragraph: A paragraph is a block of text that presents information or instructions using written statements. It does not rely on pictures or visual elements to illustrate the task.

d) An if-then table: An if-then table is a logical statement that outlines different scenarios or conditions along with corresponding actions or outcomes. While it may contain text-based instructions, it does not primarily rely on pictures to illustrate the task.

Considering the above analysis, the option "b) A diagram" best fits an instruction format that uses pictures to illustrate a task.