2. a) Explain the following code and indicate in each case the type of addressing mode used. iCMA ii) MVI B, 45 ii) LDA 4000 iv) LDAXB I8 Marksl b) Give five (5) types of addressing modes of 8086 with an example in each type. 5 Marks c) Treat R6-R7 and R4-R5 as two 16 bit registers. Perform subtraction between them. Store the result in 20h (lower byte) and 21h (higher byte) of 8051 Memory. 7 Marks