An embedded system uses RS$232$ with the following frame format. The system receives a message of five characters. An oscilloscope is used to monitor the signal and the five characters are shown below. We know that the RS$232$ is reliable and at least more than $50\%$ frames received are correct. Please answer the following questions: a$)$ What are the five characters received? You need to provide detailed steps to get full marks. $[5$ marks$]$ b$)$ Which of the following code should be correct? You need to provide a detailed explanation to get full marks. Serial.begin$(9600,$ SERIAL$\_7$E$2)$; Serial.begin$(9600,$ SERIAL$\_7$O$2)$; $[4$ marks$]$ c$)$ Which of the five characters received is$/$are incorrect if there is a technical error caused by strong environmental noise? $[3$ marks$]$ d$)$ How much time does it take to receive the five characters if we use the correct code in the previous sub$-$question $(2)?[3$ marks$]$