1. in and of.
2. in.
3. to.
4. of.
5. into (off could be a preposition but in this case is part of the phrasal verb 'to send off')
Answer B. (Future perfect tense is used, as the sentence refers to something that will be completed by some point in the future.) is correct.
B is correct because the event which will happen in the future (the baking of the cakes) will also have ended.
I will have baked is a correct form of future perfect, because future perfect is made with the following construction:
Subject + will have + past participle
Hardware refers to the physical and visible components of the system such as a monitor, CPU, keyboard and mouse. Software, on the other hand, refers to a set of instructions which enable the hardware to perform a specific set of tasks.
