Answer:
Option B. 8
Step-by-step explanation:
[tex]1 \frac{3}{4} d = 14[/tex]
[tex] \frac{7}{4} d = 14[/tex]
[tex]d = 14 \times \frac{4}{7} [/tex]
[tex]d = 8[/tex]
Hence, required value of d is 8.