!<Answer>!
According to the given linear model equation, y = 3.4x + 43, the variable x represents the number of coupons issued and y represents the number of pizzas sold.
To find the average number of pizzas sold in one night when no coupons are issued, we need to substitute x = 0 into the equation.
y = 3.4(0) + 43
y = 0 + 43
y = 43
Therefore, according to the model, the average number of pizzas sold in one night when no coupons are issued is 43 pizzas.
Therefore, the correct answer is:
43 pizzas
~ Sun
