3. A store sells two types of goods, A and B, both priced at 1800 yuan, where good A yields a profit of $20 \%$, and good B incurs a loss of $20 \%$. If one unit of each good is sold simultaneously, then, ( ).
(A) a total profit of 150 yuan
(B) a total loss of 150 yuan
(C) neither profit nor loss
(D) none of the above answers is correct
3.B.

According to the problem, the purchase price of product A is
$$
1800 \div(1+20 \%)=1500 \text { (yuan), }
$$

and the purchase price of product B is
$$
1800 \div(1-20 \%)=2250 \text { (yuan). }
$$

Therefore, the store's profit is
$$
1800 \times 2-(1500+2250)=-150 \text { (yuan), }
$$

which means the store incurs a loss of 150 yuan.