I have a test where I am given the following article, what is an answer for the question: What is the name of the fastest picking speed song by the band that recorded Kill 'Em All? ?

Music writers opine that Ride the Lightning exhibited greater musical maturity, with sonically broader songs than Kill 'Em All, which was noted for its one-dimensional sound. This was partially because of bassist Cliff Burton's knowledge of music theory. He showed Hetfield how to augment core notes with complementary counter-melodies and how basic guitar harmony worked, which reflected on the song compositions. Hetfield developed more socially aware lyrics, as well as ominous and semi-philosophical references. Ulrich explained that Metallica opted not to rely strictly on fast tempos as on the previous album, but to explore other musical approaches that sounded powerful and heavy. Grinder magazine's Kevin Fisher summarized the album as "ultimate thrash, destruction and total blur" that reminded him of the speed and power of Kill 'Em All. Music journalist Martin Popoff observed that Ride the Lightning offered "sophistication and brutality in equal measure" and was seen as something new at the time of its release. Discussing the album's lyrical content, philosopher William Irwin wrote: "After Kill 'Em All, the rebellion and aggression became much more focused as the enemy became more clearly defined. Metallica was deeply concerned about various domains in which the common man was wrongfully yet ingeniously deceived. More precisely, they were highly critical of those in power".
The major-key acoustic introduction to "Fight Fire with Fire" displayed Metallica's evolution towards a more harmonically complex style of songwriting. The fastest Metallica song in terms of picking speed, it is driven by nimbly tremolo-picked riffs in the verses and chorus. The extended solo at the end dissolves in a sound effect of a vast nuclear explosion. The main riff was taped during the Kill 'Em All Tour and the acoustic intro was something Burton was playing on acoustic guitar at the time. The song discouraged the "eye for an eye" approach, and its lyrical themes focused on nuclear warfare and Armageddon. "Ride the Lightning" was...

Fight Fire with Fire