Fill in the blanks and select the correct option.
• The join of two adjacent vertices is called an`underline(P)`
• A `underline(Q)` is one that does not cross itself.
• Two or more distinct lines meeting at a point are called `underline(R )` lines.

Options

A. `{:(P,Q,R),("Diagonal"," Simple curve"," Concurrent"):}`
B. `{:(P,Q,R),("Edge", "Curve", "Parallel" ):}`
C. `{:(P,Q,R),("Diagonal", "Curve","Parallel" ):}`
D. `{:(P,Q,R),("Edge","Simple curve", "Concurrent" ):}`

Answer

To solve the question, we need to fill in the blanks with the correct terms based on the definitions provided. Let's break it down step by step.

### Step-by-Step Solution:

1. **Identify the first blank (P)**:
- The statement is: "The join of two adjacent vertices is called an ___".
- In geometry, when we connect two adjacent vertices, the line segment formed is known as an **edge**.
- Therefore, we fill in the blank: **P = edge**.

2. **Identify the second blank (Q)**:
- The statement is: "A ___ is one that does not cross itself".
- A curve that does not intersect itself is referred to as a **simple curve**.
- Therefore, we fill in the blank: **Q = simple curve**.

3. **Identify the third blank (R)**:
- The statement is: "Two or more distinct lines meeting at a point are called ___ lines".
- When two or more lines intersect at a single point, they are called **concurrent lines**.
- Therefore, we fill in the blank: **R = concurrent lines**.

### Final Answers:
- P = edge
- Q = simple curve
- R = concurrent lines

### Conclusion:
The correct option that fits all the filled blanks is **D**: P is an edge, Q is a simple curve, and R is concurrent lines.

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