Option A: 2
If zeroes are reciprocal, their product = 1. Product of zeroes = $\dfrac{2a/b}{a} = \dfrac{2}{b} = 1$, so b = 2.
Source: Chapter 2, Section 2.3
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When zeroes are reciprocals of each other (say α and 1/α), their product = 1. Using the formula: product of zeroes = constant term ÷ coefficient of x², set $\frac{2a/b}{a} = \frac{2}{b} = 1$, giving b = 2. Don't confuse the constant term here — it is $\frac{2a}{b}$, not just 2.