TD - An Asian option, a lookback option and a stop-loss option

Question
Explain the major difference between an ASIAN option and a LOOKBACK
option. Based on general financial arguments, would you expect a Lookback
option to more or less valuable than its European vanilla equivalent?
A STOP-LOSS option may be regarded as a perpetual barrier lookback Put
which pays a fixed proportion λ of the maximum realized asset price J if
ever the asset price falls below some barrier which will be denoted by λJ,
(λ < 1). Assume that a stop-loss option is written on an underlying that pays
a continuous dividend yield D0. By seeking a time-independent solution to
the Black-Scholes equations (with suitable boundary conditions) of the form
V = JW(S/J)
value this option. What is the major financial reason for buying such an
option?
What value does the option have when D0 = 0? Give a financial interpretation of this result.