EAC calculations

Actual cost=$1000,
Budget at completion=$800,
cost performance index=0.5,
Earned value= $600, the variance can occur again.

The estimate at completion is:

a) $1000
b) $1400
c) $800
d) None of the above

Could you please specify your answer and calculations

If you catch this line " the variance can occur again " then the formula which could be used here is

EAC=AC+[(BAC-EV)/(CPI x SPI )]

Answer is B=1400 based on other web sites.

CPI=600/1000=0.60 EAC=800/0.6 = 1333

The given figure are wrong.

How come CPI=.50 while EV=600 and AC=1000. here CPI = 600/1000= 0.60

Thanks sunku65. That is exactly what I was trying to figure out.
So I can conclude the question is wrong?