Grid Pattern Analysis: Identifying Marked Regions in a 10-Unit Structure

To determine the fraction of the area that is shaded, we need to analyze the diagram carefully.

• Step 1: Count the total number of squares in the grid.
• Step 2: Count the number of shaded squares.
• Step 3: Calculate the fraction by dividing the number of shaded squares by the total number of squares.
• Step 4: Compare this fraction with the given choices.

Now, let's execute each step:

Step 1: The grid is structured in terms of columns and rows. Observing the entire structure, we find that there are clearly 10 columns and 1 row of squares, leading to a total of $10 \times 1 = 10$ squares in the grid.

Step 2: Each square width equals that of one column; 4 shaded sections fill up to 5 sections of columns horizontally:

• Two small shaded squares (1 width) plus one square is completely filled as part of two columns, making up 2 columns in total.
• One large shaded rectangle (5 width) fully occupies the width of a large single square (2 columns), counting as 5 columns (2 + 3 more), confirming 2 + 3 column segments cover it.

Step 3: Simplifies the amount as layed means $5$ shaded parts.

Step 4: Thus, the fraction calculated is $\frac{5}{10}$, which simplifies to $\frac{1}{2}$.

The correct answer choice corresponds to choices b and c as $\frac{5}{10}$ and $\frac{1}{2}$ are equivalent by simplification.

Therefore, the answer is:

Answers b and c