If m = (tb2)/xy + t, express t in terms of m, b, x and y.

For a quadratic equation $ax^2 + bx + c = 0$, we have:
$a = 2$
$b = -10$
$c = 8$

The sum of the roots is given by the formula $\alpha + \beta = -\frac{b}{a}$.

The product of the roots is given by the formula $\alpha \beta = \frac{c}{a}$.

To add the fractions, find a common denominator:

Now, substitute the values found in Step 2 and Step 3:

The calculated value is $\frac{5}{4}$. Comparing this with the given options, it matches option A.

The final answer is $\text{A. } \frac{5}{4}$.