Consider the following page reference string: 6,2,5,8,4,2,0,1,4,0,5,8 How many page faults would occur for the following replacement algorithms, assuming four frames were allocated for the process? ( fill in the blanks use numbers only) Remember that all frames are initially empty, so your first unique pages will cost one fault each. a. FIFO replacement. Number of page faults = b. Optimal replacement. Number of page faults = c. LRU replacement. Number of page faults =