The correct option is D a1
limx→∞F(x)=Llimx→∞(p1ax1+p2ax2+....+pnaxn)1/x
∴lnL=limx→∞(p1ax1+p2ax2+....+pnaxn)x
Using L' Hospital's rule
lnL=limx→∞p1ax1lna1+p2ax2lna2+....+pnaxnlnanp1ax1+p2ax2+....+pnaxn (i)
Dividing by ax1 and taking limit, we get
limx→∞(a2a1)x,(a3a2)x, etc.
All vanishes as x→∞. Therefore,
ln=Lp1lna1p1=lna1
or L=a1
Hence, option 'C' is correct.