30 Figure 4C.—Logic circuit. IN ANSWERING QUESTIONS 4-12 THROUGH 4-14, REFER TO FIGURE 4C. 4-12. What type of circuit is shown in the figure? 1. Full adder2. Subtracter adder 3. Double half adder4. Double exclusive OR 4-13. If A and B are 0 and C is 1, what will be the outputs at D and E? 1. D = 0, E = 0 2. D = 0, E = 1 3. D = 1, E = 0 4. D = 1, E = 1 4-14. Under which of the following conditions will outputs D and E both be HIGH? 1. A, B, and C are HIGH 2. A and B are HIGH, C is LOW 3. A and B are LOW, C is HIGH 4. A, B, and C are LOW 4-15. What is the largest sum that can be obtained from a full adder? 1. 10_{2}2. 11_{2}3. 100_{2}4. 111_{2}4-16. How many full adders are required to form a parallel adder capable of adding 10001_{2} and 1000_{2}? 1. Five 2. Six 3. Three 4. Four