McCabe’s Cyclomatic Complexity is a metric used to measure the complexity of a program. It is calculated using the formula:

Cyclomatic Complexity=E−N+2P\text{Cyclomatic Complexity} = E - N + 2PCyclomatic Complexity=E−N+2P

where:

E = number of edges in the flow graph

N = number of nodes in the flow graph

P = number of connected components (usually 1 for a single program)

In the given program, there are 2 decision points (IF and THEN). The cyclomatic complexity is calculated as:

Cyclomatic Complexity=2−1+2=3\text{Cyclomatic Complexity} = 2 - 1 + 2 = 3Cyclomatic Complexity=2−1+2=3

Hence, the answer is B. Reference: ISTQB CTFL Syllabus V4.0, Section 4.3.2​​.