Correct Answer: chm

Solution : Given:
aebd_fjgi_koln_

To fill the series we have to divide the series – aebd_ / fjgi_ / koln_
Let's check each option –
First option: cmh; aebd c / fjgi m / koln h (No pattern has been found.)
Second option: chm; aebd c / fjgi h / koln m (In each part, add 5 to the place value of each letter.)
First letter of the series→a + 5 = f; f + 5 = k
Second letter of the series→e + 5 = j; j + 5 = o
Third letter of the series→b + 5 = g; g + 5 = l
Fourth letter of the series→d + 5 = i; i + 5 = n
Fifth letter of the series→c + 5 = h; h + 5 = m
Third option: cgm; aebd c / fjgig / koln m (No pattern has been found.)
Fourth option: cjl; aebd c / fjgi j / koln l (No pattern has been found.)

So, the series becomes aebdcfjgihkolnm. Hence, the second option is correct.