(c) Various microcontrollers are applied for various applications. Given an 8051, an Arduino UNO, and an ARM Cortext M4 microcontroller boards with no external memory attached, select which board is more suitable for each of the following applications. Justify your answer for each. Assume that the 8051 is the cheapest, ARM Cortext M4 being the most expensive, and the cost of the Arduino UNO is in between. A water heater system that employs a heating coil to heat up water to a preset temperature. The system then maintains the temperature of the water at the preset temperature. II A portable energy monitoring system which records real time current consumption of a device every second. The average value over the last 10 seconds is constantly displayed to the user. The highest current usage every minute is also stored in memory for up to 1 day and can be sent to the display when requested by the user. III A security system which allows a single user to key in a 6-digit pin code through a Keypad to lock and unlock a door. Up to 2 users with unique 6-digit pin code is supported. The pin code is also be programmed through the keypad by the user. IV A measurement system that employs an array of 3 high gain antennas to monitors wifi signals. The system is able to perform signal processor on the signals received by the antenna array to determine the number of wifi sources, and the direction of the 3 wifi sources with the strongest signal. The total number of wifi sources, and the direction of the 3 wifi sources are then displayed on a digital LCD display